Chapter 4. The Statistical Efficiency Conjecture

  1. Shirley Coleman Technical Director6,
  2. Tony Greenfield7,
  3. Dave Stewardson6 and
  4. Douglas C. Montgomery8
  1. Ron S. Kenett1,2,
  2. Anne De Frenne3,
  3. Xavier Tort-Martorell4 and
  4. Chris McCollin5

Published Online: 3 MAR 2008

DOI: 10.1002/9780470997482.ch4

Statistical Practice in Business and Industry

Statistical Practice in Business and Industry

How to Cite

Kenett, R. S., De Frenne, A., Tort-Martorell, X. and McCollin, C. (2008) The Statistical Efficiency Conjecture, in Statistical Practice in Business and Industry (eds S. Coleman, T. Greenfield, D. Stewardson and D. C. Montgomery), John Wiley & Sons, Ltd, Chichester, UK. doi: 10.1002/9780470997482.ch4

Editor Information

  1. 6

    Industrial Statistics Research Unit, Newcastle University, Newcastle upon Tyne NE1 7RU, UK

  2. 7

    Greenfield Research, Little Hucklow, Buxton SK17 8RT, UK

  3. 8

    Regents' Professor of Industrial Engineering & Statistics, ASU Foundation Professor of Engineering, Department of Industrial Engineering Arizona State University Tempe, AZ 85287-5906, USA

Author Information

  1. 1

    KPA Ltd., P.O. Box 2525, Raanana 43100, Israel

  2. 2

    University of Torino, Torino, Italy

  3. 3

    Math-X sprl, Brussels, Belgium

  4. 4

    Technical University of Catalonia (UPC), Barcelona, Spain

  5. 5

    Nottingham Trent University, Burton Street, Nottingham NG1 4BU, UK

Publication History

  1. Published Online: 3 MAR 2008
  2. Published Print: 7 MAR 2008

ISBN Information

Print ISBN: 9780470014974

Online ISBN: 9780470997482



  • competitive pressures and customer expectations;
  • quality by design (QbD);
  • statistical efficiency conjecture;
  • four-step quality ladder;
  • key process output variables (KPOVs);
  • project-by-project improvement strategy;
  • Six Sigma business improvement strategy;
  • MINITAB macro;
  • DMAIC roadmap;
  • Weibull distribution analysis software


This chapter contains sections titled:

  • The quality ladder

  • Improvement projects

  • Six sigma

  • Practical statistical efficiency

  • Case studies

  • Conclusions

  • References

  • Appendix 4A